Angina

(Angina pectoris, chest pain, coronary artery disease)

Angina is recurrent chest pain that originates under the breastbone (sternum), often spreading to the neck, jaw, arms, and upper back. The nature of the pain varies, but it is usually described as a sensation of pressure, tightness, heaviness, or choking, and it is often accompanied by shortness of breath. Severe angina may feel like a heart attack, but it is a temporary condition that does not cause permanent damage. It does, however, signal an increased risk of a heart attack.

Angina occurs when the heart muscle is not getting enough oxygen. The most common cause is atherosclerosis, a narrowing of the coronary arteries due to deposits of fatty plaque. The narrowed arteries may be able to deliver enough oxygen-rich blood to the heart muscle to carry on normal activities, but when the heart must work harder, such as during unaccustomed physical exertion or periods of stress, the heart muscle becomes starved for oxygen, a condition called ischemia.

A heavy meal or exposure to cold may also precipitate angina because blood flow is diverted from the coronary arteries to other parts of the body. Some people experience angina while resting or even sleeping. This unprovoked, or variant, angina is sometimes caused by a spasm in the coronary artery, usually at the site of fatty deposits. More often, it is classified as unstable angina, and is a warning sign of impending heart attack.

Diagnostic Tests and Procedures

There is no specific test for angina, but a doctor can usually tell whether or not the pain arises from the heart by asking three key questions:

1. What provokes the discomfort?
2. What is it like?
3. And what alleviates it?

Angina is suspected when there are other cardiovascular risk factors, such as cigarette use, a family history of early heart attacks, elevated blood pressure and cholesterol levels, diabetes, and so forth. During a physical examination, the doctor listens carefully to the heart for any abnormal sounds or beats.

Routine tests include an electrocardiogram (ECG), blood pressure measurement, blood and urine tests, and a chest X-ray. If a doctor suspects angina, additional tests may be ordered to assess any underlying heart disease. An exercise stress test can usually confirm that physical exertion brings on ischemia. This test is sometimes combined with echocardiography, an examination using high-frequency sound waves, or nuclear scanning, in which thallium or another radioactive substance is injected into the bloodstream and then tracked by special gamma cameras. These last two tests can often pinpoint the areas of heart muscle that are deprived of blood.

A more invasive procedure, cardiac catheterization, is needed to make a precise diagnosis of coronary artery disease. In this examination, a thin, flexible tube is inserted into an artery in the leg (or less commonly, the arm) and threaded to the heart. A dye is then injected into the coronary arteries to make them visible on X-rays.

Medical Treatments

There are numerous effective treatments for angina, ranging from exercise conditioning and medication to surgery. Depending upon the severity of symptoms and the degree of coronary disease, lifestyle changes and drugs are usually tried first, with surgery reserved for cases that cannot be controlled by more moderate approaches.

Exercise Conditioning. After an exercise stress test, a doctor prescribes a regimen of physical activity designed to increase endurance without provoking angina. Patients are taught to monitor their heart rate, and to increase their exercise gradually. This conditioning prompts the coronary arteries to build collateral circulation, increasing blood flow to segments of the heart muscle receiving inadequate blood.

Drug Therapy. There are numerous drugs that control or prevent angina. The choice depends on the circumstances and whether or not there are other contributing disorders, such as high blood pressure.

Two classes of drugs -- nitrates and calcium channel blockers -- open, or dilate, the arteries, allowing more blood to flow through them. This action lowers blood pressure, reduces the heart's workload, and increases blood flow to the heart muscle. A third class of drugs, beta blockers, alleviates angina by reducing the action of norepinephrine, a neurotransmitter that carries signals from the sympathetic nervous system. Blocking these signals also reduces the heart's workload by allowing it to beat slower and less forcefully than usual

Calcium channel blockers and beta blockers are taken daily to prevent angina; nitroglycerin -- the most commonly prescribed nitrate -- is used both to stop and prevent angina. During an attack, a nitroglycerin pill placed under the tongue or in the cheek pocket is absorbed rapidly into the bloodstream, usually providing relief within five minutes. The effect wears off quickly, however; for more sustained or preventive action, nitroglycerin is available as a skin patch or ointment. In these forms, the drug is slowly absorbed through the skin, thus providing protection from attacks.

A note of caution: Nitroglycerin can cause flushing, dizziness, and head-ache. Doctors advise sitting down when taking the medication: This reduces dizziness and prevents fainting from a sudden drop in blood pressure.

Angioplasty. This is an invasive procedure designed to alleviate angina by physically opening up narrowed blood vessels. It is similar to cardiac catheterization, except that a catheter with a balloon tip is inserted into the coronary arteries while being followed on a fluoroscope monitor, a special type of moving X-ray. When the catheter reaches a narrowed segment, the balloon is inflated to flatten the plaque. In a new variation, a rotating blade similar to a tiny roto-rooter shaves the plaque into tiny particles, rather than simply flattening it out. In another, still experimental variation, a laser beam is used to vaporize the plaque.

Coronary Bypass Surgery. This operation is reserved for severe coronary disease that cannot be adequately controlled with drugs and is not amenable to angioplasty. Segments of healthy blood vessels, from either an artery in the chest wall or a vein in the leg, are used to bypass severely narrowed parts of the coronary arteries. Up to seven or even eight bypass grafts may be done in a single operation, greatly increasing blood flow to the heart muscle and reducing the incidence of angina and the risk of a heart attack.

The operation usually takes 3 or 4 hours, although some complicated cases require 8 to 10 hours. The patient then spends two or three days in an intensive care unit, and another five to seven days in the hospital. Even though the operation is relatively safe, it is not risk-free, and the potential dangers must be weighed against the benefits that are expected.

Alternative Therapies

Angina is always a serious warning sign, and any alternative therapy should be considered an adjunct to, not a substitute for, conventional medical treatments. A number of prominent researchers and cardiologists have been trying out combinations of conventional and alternative therapies, especially in preventive cardiology. Alternative approaches include:

Exercise Conditioning. This involves following a specific exercise regimen to improve cardiovascular function. The objective is to increase physical activity without provoking an attack of angina. After undergoing an exercise stress test to determine his maximum safe exercise level, the patient is given an exercise program calling for gradual increases in activity. With conditioning, the heart pumps more efficiently, and the body also uses oxygen more efficiently, reducing the hearts workload. Exercise also helps build collateral coronary arteries to increase blood flow to heart muscle.

Herbal Medicine. To treat angina, herbalists recommend hawthorn, sweet woodruff, and a number of other herbs that increase blood flow. They also advocate garlic to prevent angina by attacking its underlying causes, high blood cholesterol as well as high blood pressure. (An odorless garlic pill is available; whether or not it has the same benefits as fresh garlic has not yet been determined.)

A note of caution: Some highly toxic plants such as foxglove (digitalis) are used to make prescription heart medicines, but brewing your own drugs from them can be fatal.

Meditation and Yoga. These are among the relaxation techniques being used by researchers who are studying their potential in treating angina and coronary heart disease. The initial results indicate that for some patients, these alternative therapies reduce their need for drugs and surgery.

Nutrition Therapy. Its role in coronary disease is well established. Both alternative and conventional practitioners now advocate low-fat, high-fiber diets. The late Nathan Pritikin developed a very low-fat, mostly vegetarian diet for angina patients that has since been adopted by many mainstream physicians and nutritionists. Nutrition therapists may also recommend high doses of vitamin E, an antioxidant that is believed to lower levels of the harmful LDL cholesterol. Lecithin is also advocated, but its benefits are not as well documented as those of vitamin E.

Shiatsu. Practitioners of this Japanese massage therapy believe that pressing upon points in the inner forearm can alleviate an angina attack.

Self-Treatment

It is increasingly clear that a prudent lifestyle is central in both preventing and treating the underlying coronary disease that causes angina. Especially critical factors are not smoking, getting enough exercise, controlling stress, and eating a balanced low-fat diet that is also high in fiber and complex carbohydrates. Many doctors also recommend a daily aspirin to prevent a heart attack, but check with your doctor first -- even low-dose aspirin is hazardous for people with uncontrolled high blood pressure, ulcers, and certain bleeding disorders.

The following are some specific self-help strategies for preventing angina:

• Eat four or five small meals, evenly spread throughout the day, rather than two or three large ones.
• After a heavy meal, blood is diverted to the digestive system, reducing flow to the heart and other muscles.
• Avoid exercise for at least one hour after eating.
• Go easy on alcohol. An occasional drink or two probably is not harmful, but excessive alcohol can damage the heart muscle.
• Avoid going out on cold, windy days. The cold constricts blood vessels and increases the chance of suffering an attack of angina.

Other Causes of Chest Pain

Indigestion, esophageal spasms, heart-burn, and panic attacks are among the many non-cardiac causes of chest pains. An overactive thyroid, or hyperthyroidism, can also cause irregular heartbeats and chest pain. Pericarditis, an inflammation of the sac surrounding the heart, should be ruled out, as should structural problems, such as a broken rib. Asthma, a collapsed lung, and other pulmonary disorders can also produce shortness of breath similar to that of angina.